The present invention relates to CVD-compatible tungsten halogen phosphine complex compounds and methods of synthesizing same.
In recent years, the areas of metallo-organic and coordination chemistry have experienced incredible growth due to the increasing technological importance of these fields. Examples of the broad spectrum in which metallo-organic species are utilized include the frequent application of organic synthesis, the stabilization of reactive particles such as, for example, arines, carbenes, alkines by metallic coordination, and homogeneous catalysis via intermediate organo-metal stages. A more recent utilization of compounds of this species is the use of metal deposition, from these compounds, utilizing CVD-methods (chemical vapor deposition). To accomplish such a deposition, metal complexes that are readily volatile and thermically decomposable are necessary.
An article by Th. Kruck in the periodical "Angewandte Chemie" 79 (1967), pages 27-43, discloses the purification of an inorganic ligand trifluorophosphine. It has been found that an acceptor capability at the ligand PF.sub.3 is present in this compound that is greater than that of the previously known transition metal carbonyls.
From another article by Th. Kruck et al, in the periodical "Anorganische Allgemeine Chemie" 397 (1973), pages 31-39, a compound, hexakis (trifluorophosphine) tungs (0) having the chemical formula W(PF.sub.3).sub.6 can be derived. Utilizing a method of "reductive trifluorophosphination" results in a 42% yield of the compound.
German Published Application No. 1 900 119 also discloses the use of metal trifluorophosphines. Metal layers, that are used as contact metal layers in semiconductor technology, are deposited on substrates by a thermic decomposition of metal (0) complexes, known at that time and their hydride derivatives, at temperatures from 350.degree.-600.degree. C. and reduced pressure.